Across Europe the protection of research subjects with dementia has to meet a variety of national legislation and ethical codes. This research project compared how in different EU countries one single descriptive multinational study on dementia treatment strategies was evaluated by medical ethical committees and how the issues of informed consent and capacity to consent were dealt with. The study that was evaluated is the ICTUS study, which studies the impact of treatment with acetylcholinesterase inhibitors (AChE-I) on Europeans with mildly or moderately severe Alzheimer's disease (AD). Participating centres in all 12 countries that take part in the study received a questionnaire with items on the process of approval by the ethical committee and the informed consent procedure. From the 29 centres we received 21 completed questionnaires (response rate of 72%). There were great differences in valuation of the study, varying from the judgement that the ICTUS study was 'no experimental study' to the judgement that it was a phase IV drug trial. All centres got approval, after 3-90 days. Informed consent was addressed very differently by the researchers. There was no formal informed consent procedure required by the ethical committees. The data from this survey suggest that there should be more consensus across the EU about which studies or interventions do and which do not require approval of an ethics committee. Procedures for the assessment of informed consent in dementia research should be harmonized by central national or European bodies.